Improperly positioned teeth may be forced into desired positions through the use of a flexible wire, referred to by orthodontists as an archwire, and a series of appliances affixed to respective upper and lower teeth. The appliances currently take the form of specialized brackets and buccal tubes formed from suitable metallic or ceramic or plastic material. The orthodontist typically adheres the appliances to the teeth with an adhesive, although other fixation methods are known as well. Each appliance includes a slot or a hole to receive and control the position of the archwire.
The design of orthodontic appliances involves the balancing of several considerations. The appliance must adequately retain and position the archwire and further allow for adjustments to the archwire. Preferably, appliances are compatible with other dental attachments with minimal complexity and are strong yet compact. The most common bracket design is the so-called tie-wing bracket. This bracket includes a slot for insertion of the archwire and a plurality of projections referred to as wings. After the archwire is set in the slot of the bracket, either a tie wire or an O-ring is affixed beneath the wings and over the archwire at each end of the archwire slot. The tie-wing bracket is a simple design and provides excellent control of the archwire. Brackets of this type typically have parallel upper and lower surfaces of adequate size to be easily gripped with conventional orthodontic pliers. However, some orthodontic appliances are generally tubular in shape or otherwise have nonparallel, opposite surfaces. These appliances include buccal tubes used on rear molars to anchor and hold the archwire ends in proper alignment.
In one prior buccal tube design, for example, one outer surface slopes downwardly from a position close to the base or tooth mounting surface and an opposite outer surface extends essentially perpendicular from the base. A small gripping ledge is contained on the body of the buccal tube and intersects the sloped surface. In addition to facilitating patient comfort, one of the main functions of the sloping surface is to deflect food particles which may become lodged between respective buccal tubes of the upper and lower teeth as the patient chews food, especially hard foods such as hard candy, etc. Unfortunately, the sloping surface also impedes the ability of the orthodontist to grasp the buccal tube with a pair of conventional pliers during installation or removal procedures. The small gripping ledge on the body of the buccal tube is not easily grasped at all times and the orthodontist may therefore experience "shoot-out" of the buccal tube from the tool as one of the gripping jaws of the tool slides down the sloping surface.
While it would be desirable to continue providing one or more sloping surface in many orthodontic appliances, it would also be desirable to provide a orthodontic appliance, such as a buccal tube or other orthodontic bracket or appliance, with better gripping ability despite the presence of opposite, nonparallel appliance surfaces.